Dustin Moskovitz's new foundation, Good Ventures, may have only a skeletal staff, but it's now definitely up and running, with his life partner, Cari Tuna, at the helm. Grants are going out the door, including major support for the Center for Global Development. (Read IP's profile for Good Ventures Foundation.)

We'll have a lot more to say about Good Ventures in coming months. But one point that nobody should forget about Moskovitz's philanthropy is that he plans to spend down his Facebook fortune in his lifetime. That's a crucial point that shouldn't get lost in the attention to the details about what Good Ventures is doing.

Moskovitz — the world's youngest billionaire, with a reported 7.6% stake in Facebook — has decided to turn his attention immediately to large-scale philanthropy, unlike many tech winners who leave the process of giving their money away till later. Moskovitz is a signer of the Giving Pledge, and the letter he posted on the Pledge site, written with Cari Tuna, explains how he is thinking:

As a result of Facebook's success, I've earned financial capital beyond my wildest expectations. Today, I view that reward not as personal wealth, but as a tool with which I hope to bring even more benefit to the world.

I'm grateful to my friends and family for shaping my understanding of effective philanthropy, educating me on areas of need, and demonstrating time and again the power of a good idea, well executed. . . .

Over the next few years, we will begin to identify the causes to which we can make the most leveraged contributions. We will donate and invest with both urgency and mindfulness, aiming to foster a safer, healthier and more economically empowered global community.

Well before Facebook went public, Moskovitz and Tuna were already doing their homework on philanthropy, talking to people about how they could give most wisely. Through this process, Moskovitz decided he would try to give away all his money while he is still alive.

Moskovitz has embraced the case for earlier giving, which is that such giving can stop problems from snowballing: "By investing in philanthropy now, assuming I can find ways to create true impact, the good created will compound as well. In the end, less capital may need to be put to work to create the same overall impact."

In particular, Moskovitz believe that "poverty is a solvable problem and that it will be solved in the very near term." (By which he means 30 years or so.) "If you can get people to a level of sustainability, those communities will thrive, and then you won't need more money later on to help a larger population of people that have grown up in poverty."

There's much logic to this view, even if Moskovitz seems overoptimistic about solving poverty. (But his can-do thinking, too, seems like an asset.) If one key to ending poverty is disrupting the intergenerational transmission of disadvantage, the sooner big money is spent toward this end, the better.

As for the goal of spending down his fortune, Moskovitz understands the challenge before him and Tuna: "We basically intend to fully spend the capital, and if you're thinking about giving away money at that kind of volume, you need to stop learning now. It will take us a decade just to get to full capacity."

Moskovitz says he doesn't intend to leave significant capital to the next generation.

Judging by the experience of other billionaires who have sought to spend down in their lifetime, most notably Chuck Feeney, Moskovitz will have to build a foundation with the capacity to move hundreds of millions of dollars out the door every year. This will be even more true if the value of his Facebook stock rises above where it is at this writing (in the $20s per share).

Creating Good Ventures is the first step in that process. And Moskovitz is right that getting Good Ventures to scale and figuring out where to focus may take a decade — at which point Dustin Moskovitz will be all of 37. (See Good Ventures Foundation: Grants for Global Development.)